Grinding machine



May 18, 1948. J. H. woRTHEN 2,441'784 GRINDING MACHINE Filed Nov. 15, 1944 3 shees-sneet 1 ;of W

INVENTOR /0/J0/,z7//Mf/4/z ATTORNEYS May 18, 1948.'

J. H. WORTHEN GRINDING MACHINE Filed Nov. 15, 1944 3 Sheets-Sheet 2 INVENTOR 'rToRNEYs I 18, H WORTHEN GRINDING MACHINE Filed Nov. 15, 1944 5 Sheets-Sheet 3 INVENTOR Patented May 18, 1948 i GRINDING MAonmE John H. Worther'n:Providence, R. Ii', assignor to Federal Products Corpor- Rhode Island w w ation, a corporation of Application November 15, 1944, serial No. 583,487

This invention relates for sharpening relatively small cutters such as hobs for instrument gears.

The usual tool room grinders are large and inconvenient for use on small work and are so made that particles of `abrasive fromvthe wheel frequently get into the mechanism. On the other hand, some very small machines lack the rigidity and the surface which remains after contact with the grinding wheel is therefore rough.

One of the objects of this invention is to provide a small machine which will present the necessary rigidity and yet one whereby the acvide an adjustment for the work so that the' depth of cut may be very precise.

A further object of this invention is to provide a mechanism by which the precise adjustment which has been obtained may be preserved'after indexing to selectively position the Work.

Another object of the invention is to provide an arrangem-ent whereby wheel wear may be readily compensated for by adjustment or surfacing of the wheel.

Another object of the invention is to provide an arrangement whereby the working parts will be free from grinding dust.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claim.

In the accompanying drawings: i f

Fig. 1 is a top plan view of the machine;

Fig. 2 is a section on line 2-2 of Fig. 1 but showing in full the handle;

Fig. 3 is a fragmental sectional view indicating a surfacing of the wheel;

Fig. 4 is a sectional view through the work support;

Fig. 5 is a section on line 5-5 of Fig. 4;

Fig. 6 is a sectional view through the upright support looking down on top of the looking mechanism for the indexing plate;

Fig. 7 is a perspective'view of the mounting of the looking pin which engages the indexing plate;

Fig. 8 is a fragmentalperspective view illustrating the notch in which the looking pin of Fig. 7 engages; and

Fig. 9 is a sectional View showing the vlower mounting center for the Work arbor.

In proceeding with this invention I provide a work support consisting of an arbor which may be indexed about its axis in equal angular amounts all according to a predetermined series of notches which may be placed in a disc which is carried by the arbor. A looking pin is provided to hold this disc in various positions. This locking pin is mounted to move on substantially a radius toward and from the axis of the arbor' to a grinding machine 1 olaim. (cl. 51-98) ;Jwhile it may be adjusted at right angles to the i .from for mounting dead centers I3 and Aactuating electric motor.

radius by measured amounts. Thus, the work support may be nicely adjusted in measured increments. To operate upon the work I provide a cradle which carries the grinding wheel and an The cradle is counterbalanced and may be rocked toward and from the work by easily operable manual means.

With reference to the drawings, m designates a base which has standards I and E2 rising there- |4 adjustably in the supports whereby they are held by nuts |5, 'and IS, 16'. A shaft l'l is freely rotatably mounted by means of these dead centers. A U-shaped eradle designated 'generally V|8 comprising a'tub'ular 'portion lg and reari bearings 25 and 26' which are' clamped tightly upon the shaft |'l by' the handle bolts 2'l`which are threaded at 28 to engage a threaded socket* in the arm while its'head engages the opposite side of the split bearing. A shaft Z is rotatably mounted in the tubular portion IS on which the grinding wheel 2| is fixed at one end while a pulley 22 is mounted on this shaft at its 'other i end. An electric motor 30'is secured by means of bolt 3| and 32 to the underside of the arms of the cradle such as shown in Figs.. 1 and 2; An

arm 33 extends upwardly from the shaft H and a counter-weight 34 is adjustably mounted along this shaft so as to substantially equally balance the weight of the wheel 2| and motor 353, and the other overhanging parts of the cradle. The arrangement is such that the parts are in balance and an arm 36 having a handle 31 is provided attached to the cradle as at 38 so that by 'grasping this handle and rocking the cradle about the v 46 threaded inwardly to bind the holder in the .bore 43. A post 41 mounted on the base at a position below the portion E9 serves to limit the downward move-inent of the tool. This post may be adjustable as to height by' being 'reo` movable and substituted by a different height' pgt,

A work support 'is provided on a-raised portion 50 which carries a gib 5| (see Fig. 4), and a carriage`52 which is recessed as at 53 so as to' receive this gib 5|. Slots 5d and 55' (see also Fig. 6) are provided in the carriage for the reception of bolts 55 and 55' which extendthrough the slots into the base or raised vportion 50..

3 Springs beneath the'heads ofthese bolts engage wasiiers 'ii-'5 so as'to apply a guding tension upon the carriage as it is moved along the gib 5|. A dead center 58 carried by the bushing 53, is adjustable as to heig-ht by the threaded engagement 50 which the bushing has with the carriage 52. An upstanding support 6! of generally I-beam shape extends upwardly from the carriage and has a dove-tail gibi' 'for adjustably i mounting the bracket 63 which has a dove-tail 4 of the notch. An arrangement by which this may be accomplishedis a lever :103 having a handle lMwhich is provided with a hu'b m5 movable about the axis of the dead center 53. This hani dle is provided with a dog arm l provided with a pin l'l and urged by spring N38 to cause the 'pin to slide into a notch.8|.

By then urging this leve'r to the left asshown in Fig. 6 the disc may slot 64, (see Fig. 1), to receive it. This oracket-V 63 has a bore 65 to receive a dead center 66 which A collar 68 is thetsame downwardly. A handle .portion ;'H is r threaded .into the .upper end of this 'dead center and is provided with a pin 12 to engage the-socket .or recess .13. `This also serves'as ast'op to preventthezcenter'fifi from being forced'by the springthroughitsbore65.

An arbor 15 is mounted 'between thecenters i 58 and .66' andis .provided with aztaper 16' :for the1reception of the work .1:1 which islheld snugly on this taper iby 'a threaded cap 1:8 and vhas a recess toreceive the center. disc .lis mounted-uponthis' arbor in afixedrelationfthereto'and is .provided with Va plurality of V-not'ches 81 in-its fiange 82,'which V-.notches fiareV outwardly'; The' pin: B3. iszresiliently mounted to enter Vthe selected one .of these notches.

This pin is .carried by van arrangement so'thatV it Ywill ;move :in a straight line ffrom. its notch whichwil1 be 'close to'a .radiallineztoward and from'the axis 'of the: arbo-r .15 van-d 'also 'will move at. right .angle to thisline. mounted upon thecarria'se .5.28 by. meansof `bolts 86. .'A'block''l is connected-totheblock 85 by' parallel :resilint Springs :8.3 andV '8.9 'of ;equal lengths 'thus -providing :a 'narallelistic movement Whreby the block; B1 Will always moveparallel to. the'block 85. Ab1ock 90is-rigidlvmountd upon'tne block 81' whileiresilientleaf isprngs :Si an d.92- lof equal length and parallel andare-ses cured tozthe block :Qbv bolts '93 Serve to carrythefblock'. lThe ,pin 83 iis'carried Ibye .slide 95 which .is adjustablyV held `by -'means1of .the bolts 9B Vsecured to the block 94. This'arrangement is so positioned that the pin 83 will have its .center on` a radius extended from'th'e-center ofthe arborxto the notch -engaged The reslient members 9| and 92 willcause the pin'to move alwayssubstantially parallel to this Vr-adius while the relative arrangement of the two parallelistic movements is vsuch that the springor tresilient members 88 and-89V willzcause any movement of the `block'l and-consequently the movement of the pin .83 whiohis carried thereby to be at substantiallyv right -anglesto this radia] line.

A .mi-crometer spindle VVhas an -abutment .end 98 to engge an abutment 89 at thelower end of .thesupporting arm. 6|. Thebarrel. 10.9 will.

A circular `plate or.

;be rotatively u'rgedwith a force sufiicient to wedge the pin 83 Voutofa notch and permit it to ride alongthefiange 82-until another notch is reached when it will snap into this notch by the resiliency of thesprings 9| and 92.

In use work is positioned and then the Cutting faceof the'grinding .wheel is brought up against the surface'which is to be cut; -A reading is noted.

on the micrometer barrel IN) and then the thimble HH is turned so as to cause the pin 83 to be moved so as to positionthe disc the'number of thousands which is desired to remove from the work, the wheel of course having first been removed from .engagement with the work. This pin moves at right angles to the radius and causes f the work to movethe amount desired toV be reinoved by the wheel. Then when the handle :il

is grasped and moved -to swing the -wheel into engagement withV the work the predetermined amount of cut is taken on the work and the precise amount is remove'd. Afteronetooth of 'the hob gear or work is cut the handle HM :is

movedto rotate the disc so that the next-V- notch comes into engagement with the pin 88 which is laidout to similarly position the next .tooth Vof the hob and then th same amountof 'removal may be had from this tooth and so on i until grinding ofV all ofthe teeth is performed,

indicate the amount to which the thimble I O! is sufiifcient ;resiliencyin-.the arms. 9.! and 92,50: that the :pin Vmay move out of the notch if the disc 80. is'rotated under Fsuifloient pressure to .cause the curvature of .the pin to wedge 'the pin 'outVV VIf it is desired tosurface the Cutting edge of thewheel, post-.4'l`wi11 'be either removed or low- .ered and a lower swinging of the VVcutterwill be had to surface the .Wheel by reason of the diamond Zin'thehOIdei-Jit.

I claim:

In 'a grinding machine, a tool movable into en- -gagement with a piece of work, a work support comprisin-g an arbor for mounting` the work, a v

yengagement of said disk and member, and:a-second set of .parallelistic flexible arms for movement of said member at right angles to the movement of the first set of arms, and means for ad'- justing the second setof parallelistic fiexible arms 1 ato move Vthe member generallyV tangen'tially of REFERENCES CITED v The :following references are of record in the fiie of this patent: A

UNITED STATES VTEUi'IEiT'L w w Date Number Name 1,858,869 "VVhite May 17, 1932 1,'971,598 .condon Aug. 28, 1934' 1,985,4-.77 Vv'olfl Dec. 25, '1934 2,0%,890 l1`'erre1` Oct. 26, 1937 23176386 'B'ruestle .Oct. 17, 193.9 2,197.,538 `Dall et'al. Apr. 16, 1940: 

